Pocket adding machine



Feb. 26, 1946. w. M; ANDREWS 2,395,509

POCKET ADDING MACHINE Filed Dec. 2, 1941 i Sheets-Sheet 1 2 M. an 8% my w 3 u MM. n\ 1 A w? Feb. 26, 1946. ANDREWS 2,395,609

POCKET ADDING MACHINE Filed Dec. 2, 1941 2 Sheets-Sheet 2 Fig.8. H5. 54

INVENTOR Wayne MA/laffiews ATTO R N EYS Patented Feb. 26, 1946 UNITED STATES PATENT OFFICE POCKET ADDING MACHINE Wayne M. Andrews, New York, N. Y.

Application December 2, 1941, Serial No. 421,289

7 Claims.

The present invention relates to adding and subtracting mechanisms, more particularly of the type incorporated in cylindrical form to be carried in the pocket, which may conveniently, though not necessarily be embodied in a mechanical pencil structure.

Among the objects of the invention are to provide a mechanism of the above type, which may be fabricated with a minimum of casting or molding equipment and which may be assembled with the greatest of ease to afford a rugged and inexpensive structure, but which nevertheless will be easy to operate and will be thoroughly reliable in service.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. l is a side elevation of one embodiment of the unit according to the invention,

Fig. 2 is a view in longitudinal cross-section on a larger scale taken on line 22 of Fig. 1, but shown with only six wheels,

Figs. 3, 4 and are views in transverse crosssection taken respectively along the lines 3-3, 4-4 and 55 of Fig. 2, a

Fig. 6 is a perspective view with parts broken away of one of the number wheels,

Fig. 7 is a view similar to Fig. 1 of a modifled form of the invention,

Figs. 8, 9, and 11 are views in transverse cross-section taken respectively on lines 8-8, 9-9, ill-Ill, and il--ll of Fig. 8.

Fig. 12 is a perspective view with parts broken I away of the outer ring of a number wheel unit, and

Fig. 13 is a view similar to Fig. 12 of the associated inner ring.

Referring now to the embodiment of Figs. 1 to 6, the adding unit is shown there incorporated in a mechanical pencil, which illustratively has conventional lead clutching equipment l5 at the tip i 8 thereof. The adding mechanism includes a longitudinal core i'l. extending in this embodiment along the shaft of the pencil and unitary with the tip. Said core is generally cylindrical and has telescoped thereover the sequence of number wheels l8, one of which is shown in Fig. 6, and each of which has the ten digits thereon. Each number wheel has a flange 26 at the right snugly bearing upon the core.

The successive number wheels are provided each with a peripheral outer fillet I! to rest in a corresponding rabbet 28 at the left, so that each is securely supported upon the rod at the right and at its left upon the next number wheel of higher denomination. The left-most wheel i8 is supported at its left end upon a rabbet 2i in the enlarged tip l8 of the core. The flange 22 of an end cap 23 which is fixed at 23 to the core rests in a similar manner in the rabbet 24 of the extreme right wheel l8.

Corresponding to each number wheel, the core has a series of bolts 28 each in a corresponding well 28 in the core and pressed outward by a confined coil spring 30. Each bolt has a tapered extremity 3| adapted to enter any of ten equidistant notches 21 in the edge of flange 28. thereby resiliently or impositively to set the number wheels in selected position.

Each number wheel has an internal gear 32, comprising twenty teeth extending as a complete internal gear contiguous to the notched flange 28, with alternate interdental spaces registering with the successive notches. The internal gear extends only-to approximately the middle of the width of the number wheel. Two contiguous teeth 32' only, are of greater width and extend preferably to the left edge of the number wheel.

The carry-over mechanism between successive wheels comprises a sequence of double-ended .pinions 35 encompassed by and meshing with the respective internal gears 32 and axially aligned in a corresponding tunnel 36 longitudinally of the core and along the periphery thereof. Each pinion unit bridges from the corresponding number wheel to that of next higher denomination. The pinion units preferably have an axial bore and they are strung upon a rod 31 which is supported at it ends in bearings 31. The teeth of each pinion are interrupted at 38 to provide two toothed crowns at the opposite ends thereof. The pinion crown at the right is adapted to mesh with the two tooth segment 32' of the associated number wheel and that at the left is in constant mesh with the internal gear 32 0f the number wheel of next higher denominations, to effect the carry-over operation.

The tip l8 and the cap 23 respectively are imprinted with arrows 33, between which the sum or difierence is to be read.

In use of this embodiment, the successive numerals .are desirably entered, starting with the units and proceeding with the successive decimal places to the left. The entry is effected in this embodiment by counting clicks, that is, for each tooth advance of each wheel, the bolt 28 clicks into the successive notches. Thus, the apparatus being initially cleared as shown in Fig. l, is used by resort to the sense of feeling.

The simplicity of the mechanism will be manifest, inasmuch as there is nothing more required than the core, and the sequence of identical number wheels and of identical carry-over pinions. The mode of assembly is simple and obvious.

In the embodiment of Figs. 7 to 13 is shown an adding mechanism in which the addition may be performed visually. The core 40 is substantially identical with that of Fig. 1. The number wheel units are composite in character, each being made up of two coacting rings, an inner ring 4| completely enclosed by an outer ring 42. The two coacting rings are connected by a releasable clutch therebetween. 'F'or this purpose, the inner ring has end clutch teeth 43, ten in number meshing with corresponding clutch teeth 44 on the inner end of the thickened inner periphery 45 of the wider outer ring 42. The inner ring has a twenty tooth internal gear 46 similar to the arrangement shown in Fig. 6, the carry-over segmental gear made up of two contiguous teeth 46' extending to the left edge of the unit adjacent the bases of the teeth of clutch 43. The springurged bolts 41 in the core 40 coact with any of ten equidistant notches 41 at the right edge of the inner ring, as in the other embodiment.

The outer ring is equipped with a window 48 through which a numeral of the inner ring is exposed. The outer ring also has an internal stop lug 49 at the left edge of its inner periphery adapted to coact with a corresponding stop finger 50 upon a metal strap which encircles the core 40 and is interposed between consecutive inner rings 4|, thereby to retain the latter against longitudinal displacement. The strap 5| has an anchoring tab 52, desirably lodged in a corresponding narrow slot in the core, and a detent embossment 53 near stop finger 55 to form a resilient latch for stop lug 49.

The right end of the unit has a cap 42 mounted thereon by screw 53 with its inner face resiliently spaced from the extreme number wheel 42 by a spiral spring 54 reacting against a washer 55 at its wider end. Spring 54 thus normally urges the outer rings 42 to the left, in which position the clutches 43, 44 are disengaged, as shown.

Each outer number wheel 42 has the sequence of digits distributed about the periphery thereof, desirably in complementary pairs as shown.

The carry-over pinions 60 may be identical with those of the other embodiment, to be encompassed by and mesh with the internal gear 46 of the corresponding ring 4|, and said pinions are retained in tunnel 62 in the core 40, just as in the other embodiment.

In this as in the other embodiment, the outer ring of each number wheel has a fillet 55 extending into a rabbet 56 of the contiguous outer ring [iii and the inner rings contiguous thereto are supported by their gear teeth upon the core. The rabbet 51 of the wheel 42 at the extreme left is embraced by flange i8 on the tip l5, and the cap :2 telescopes over the fillet 58 at the extreme righ In operation of the embodiment of Figs. 7 to 13, the outer wheel is turned until the arrow 59 thereof registers with the small digit on the contiguous wheel to which the entry is to be effected. The ring 42 is then pushed to the right against the resistance spring 54 to close the clutching engagement 43, 44 with the corresponding inner ring 4|. The outer ring i now turned until its stop lug 49 abuts the stop finger on the core and is latched by embossment 53. In this turning operation, the inner ring 4| is turned with the outer ring 42, so that the number added will be exposed through the window 48.

In the same way the operation proceeds, of successively turning to the selected digit, clutching the outer ring of each number wheel unit to its inner ring and turning back to the stop position. The sum can then be read through the series of windows 48.

It will be seen that after each completed'adding operation, the arrow 59 of the outer ring will register with the zero of the contiguous outer ring.

In adding a large digit, 9, for instance, it is not necessary to rotate the outer ring in its unclutched position for substantially a complete rotation, but it may be simply turned backward from zero to 9. It is understood, however, that in its clutched position, the wheel would have to be turned in clockwise direction, when viewed from the right in order to advance the inner ring to the corresponding extent.

It is seen that the mechanism of the embodiment of Figs. 7 to 13 is only slightly more complex than that of Figs. 1 to 6, in that there are added the straps 5| and that each number wheel is made up of two rings, but the corresponding rings in each pair are identical.

It will be understood that the mechanism in both embodiments may be used for subtraction as readily as for addition, and the complementary set of digits on the outer wheels 42 serve for the latter purpose.

The elements making up the number wheels and pinions, and if desired, the core as wellv need not necessarily be made of metal, but the construction lends itself to produeon in any of a wide variety of molded plastic rna-.erials.

As many changes could be made in the above construction and many apparently .dely different embodiments of this invention cruld be made without departing from the scope or the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A cylindrical pocket adding device comprising a core, a. series of number wheel units thereabout bearing upon said core, all of the number wheel units of the device being identical and in face-to-face relation to determine an elongated continuous cylindrical case of uniform diameter, each wheel unit being manually operable from the exterior by direct engagement of the han with the number wheel, each unit including internal gear teeth completely thereabout and spaced from the left edge thereof, two teeth of said gear extending toward the left edge thereof for carry-over operation, a series of pinions aligned in a corresponding generally cylindrical tunnel in said core said pinions having a common fixed axis of rotation and meshing at their respective left ends with the complete internal gear of one gear wheel unit and at the right with the extension teeth of the contiguous gear unit. a core having a series of spring latch members coacting with the respective number wheel units for resiliently holding the same in set position.

2. A cylindrical pocket adding device comprising a core, a series of number wheel units thereabout, bearing upon said core, all of the number wheel units of the device being identical and in face-to-face relation to determine an elongated continuous cylindrical case of uniform diameter, each wheel unit being manually operable from the exterior of each unit by direct engagement of the hand with the number wheel, and including internal gear teeth completely thereabout and spaced from the left edge thereof, two of said gear teeth being extended toward the left edge of the unit for carry-over operation, a series of pinions aligned in a corresponding generally cylindrical tunnel in said core and meshing at their left end with the complete internal gear of one gear wheel unit and at their right with the extended gear teeth of the contiguous ring unit, each number wheel unit having an associated latch comprising a spring-pressed plunger mounted transversely of the core and urged into impositive latching engagement with the internal periphery of the number wheel unit.

3. A cylindrical pocket adding device comprising a generally cylindrical core, a series of number wheel units thereabout bearing upon said core, all of the number wheel units of the device being identical and in face-to-fac'e relation to determine an elongated cylindrical case of uniform diameter, .each unit being manually operable from the exterior by direct engagement of the hand with the number wheel, means limiting said number wheels against substantial longitudinal displacement upon said core, each of said number wheel units comprising a unitary ring bearing upon said core each of said rings having ten equidistant notches on its inner periphery, a spring-pressed latch unit transversely of the core, clicking in said notches in the rotary displacement of the wheel, each wheel having an internal gear of twenty identical teeth, the alternate interdental spaces registering with said notches, a

contiguous pair of the teeth of said gear protruding toward the left, and a sequence of doubleended pinions lodged in a corresponding cylindrical tunnel in the core said pinion having a common fixed axis of rotation and encompassed by said number wheels, each of said pinions bridging across two contiguous number wheels,

the addition or subtraction being effected by turning the respective number wheels and counting clicks.

4. A cylindrical adding unit comprising a generally cylindrical core, a series of number wheel units thereon, ach of said units comprising an inner ring having numbers thereon and an outer ring encasing the latter and having a window for exposing selected numerals, spring-pressed latches in said core for resiliently retaining the inner ring in set position, a clutch connection between the constituent elements of each number wheel unit selectively to permit turning the outer element thereof relative to or with the resiliently held inner element, means for closing said clutch after setting the outer wheel element, and stop means on said core to limit the rotation of the outer ring in rotating the inner ring therewith for entry of the digit to be added, and carryover pinions ,bridging across the neighboring edges of adjoining number wheel units, meshing with the inner rings, lodged in a corresponding cylindrical tunnel in the core, and encompassed by said number wheel units.

5. A pocket adding unit comprising a core, I.

sequence of number wheel units mounted upon said core, each of said units comprising a pair of rings including an inner numeral bearing ring and an outer ring having a window for exposing the recorded digit, a cap fixedly mounted upon the core at the unit end of the assemblage, a spring intervening between the cap and the numeral wheel units, a ten-tooth clutch connection between the associated rings of each number wheel unit to permit establishment of driving connection between the two rings of any selected unit by pushing the outer element thereof toward the right against the resistance of said spring, digits marked at the lateral edges of the respective outer rings for aiding in turning any ring relative to the companion ring in unclutched position thereof, coacting stops fixed respectively on the rod and on the outer ring to determine the extent of rotary displacement of the inner ring after the rings have been clutched together, and carry-over means between consecutive number wheel units.

6. A pocket adding unit comprising a cylindrical core, a sequence of number wheel units encompassing the same, each of said units in cluding an inner number ring, and an outer ring of greater width completely embracing the inner ring, said inner ring having a ten tooth clutch at one end thereof and a coacting clutch unit on the outer ring, said inner ring having an internal twenty tooth gear, a pair only of contiguous teeth of said gear extending toward the left edge thereof, a sequence of double-ended pinions each meshing at its left with the twenty tooth gear and at the right being adapted to mesh with the two tooth gear segment at the left of the contiguous number wheel, ten equidistant notches at the right of the inner rings, springpressed latches in the core adapted to coact with said notches for resiliently retaining the inner ring in fixed position, a cap fixed on the end of said core, a spiral spring interposed between said cap and the number wheel unit at the right, and index numerals at the lateral edge of the outer rings, each of the outer rings having an internal limiting stop and a corresponding stop in the path thereof, protruding from the core.

7. A pocket adding unit comprising a cylindrical core, a sequence of number wheel units encompassing the same, each of said units including an inner number ring and an outer ring of greater width completely embracing the inner ring, straps encircling said core and interposed between consecutive inner number rings and serving to position the latter against longitudinal displacement, a cap at one end of the unit, a spring interposed between the cap and the contiguous outer ring to permit displacement of the outer ring longitudinally of the core relative to the corresponding inner rings, coacting clutch teeth on the respective rings brought into engagement by such displacement, each outer ring having a stop mg and each strap having a coacting stop finger to determine the rotary displacement, the outer ring having a window to display the number registered, and each outer ring having a sequence of digits imprinter on the edge thereof to aid the setting of the unit.

warm: as. mums; 

